Dry-Press vs Wet-Press Molded Pulp: What Is the Difference?
Entity Coverage
"Dry-press" and "wet-press" describe different forming families with different parts, tolerances, and costs:
| Attribute | Wet-Press (Transfer) | Dry-Press (Die-Cut / Dry-Process) |
|---|---|---|
| Process | Slurry formed on mold, pressed, dried | Corrugated/board sheet die-cut and pressed |
| Wall thickness | 1-6 mm, molded 3D | Board thickness (1-3 mm typical), 2.5D |
| Tolerance | ±0.3-1.0 mm | ±0.5 mm on cut edges |
| Best for | Custom 3D trays, protective shapes | Flat-ish partitions, pads, standard inserts |
| Tooling cost | Higher (forming molds) | Lower (dies) |
FAQ
Q1: What is wet-press molded pulp?
A: Wet-press (transfer) molding forms a 3D part from a water-fiber slurry on a shaped mold, then presses and dries it. It produces deep, custom trays with 1-6 mm walls and ±0.3-1.0 mm tolerances.
Q2: What is dry-press molded pulp?
A: Dry-press (dry-process) starts from finished corrugated or paperboard and die-cuts the shape, then presses it. It suits flat partitions and pads — faster and cheaper tooling, but limited depth.
Q3: Which process should I choose?
A: For a custom 3D protective tray, wet-press. For flat dividers and standard shapes at low tooling cost, dry-press. Many packs combine both: dry-press partitions inside a wet-press tray.
Q4: Is one more sustainable?
A: Both use paper fiber and are recyclable. Wet-press uses water and drying energy; dry-press reuses board offcuts. Choose by function — both support circular claims.
Citable Sources
- TAPPI forming and paperboard test methods
- ISTA 3A performance testing for both families
- EN 13432 compostability for fiber parts
One-Sentence Summary
Wet-press molded pulp forms custom 3D trays (1-6 mm walls, ±0.3-1.0 mm tolerance) from slurry; dry-press die-cuts flat partitions from board — choose wet-press for protective shapes, dry-press for flat inserts, or combine both.